Which clue can be used to identify a chemical reaction as a decomposition reaction?

Question

The reaction involves oxygen.
The reaction involves ions.
The reaction has a single reactant.
The reaction has a single product.

Answer 1

The clue that can be used to identify a chemical reaction as a decomposition reaction is "The reaction has a single reactant."

In a decomposition reaction, a compound breaks down into two or more simpler substances, which typically means it starts with one reactant.